ENGINE-ELECTRICAL 6Y-20
cause oxidized contact points. Check for these conditions
where burned contacts are experienced. An
out-of-
balance condition in the ignition system, often the result
of too much or too little condenser capacity, is indicated
where point pitting is encountered.
REPLACEMENT
Four and Six Cylinder Engine Distributor
1.
Release distributor cap hold-down screws, remove
cap and place it out of work area.
2.
Remove rotor.
3.
Pull primary and condenser lead wires from contact
point quick disconnect terminal (fig. 4i).
4.
Remove contact set attaching screw, lift contact point
set from breaker plate.
5.
Clean breaker plate of oil smudge and dirt.
6. Place new contact point assembly in position on
breaker plate, install attaching screw.
CAUTION: Carefully wipe protective film from
point set prior to installation.
NOTE: Pilot on contact set must engage match-
ing hole in breaker plate.
7.
Connect primary and condenser lead wires to quick
disconnect terminal on contact point set. .
8. Check and adjust points for proper alignment and
breaker arm spring tension (fig. 5i). Use an aligning
tool to bend stationary contact support if points need
alignment.
NOTE: The contact point pressure must fall
within specified limits. Weak tension will cause
CONTACT SET
ATTACHING
SCREW
QUICK
DISCONNECT
TERMINAL
BREAKER PLATE
ATTACHING SCREWS
chatter, resulting in arcing and burning of-the
points and an ignition miss at high speed, while
excessive tension will cause undue wear of the
contact points, cam and rubbing block. Breaker
arm spring tension should be 19-23 ounces. The
contact point pressure should be checked with a
spring gauge. The scale should be hooked to the
breaker lever and the pull exerted at 90 degrees
to the breaker lever as shown in Figure 5i. The
reading should be taken just as the points sepa-
rate.
The pressure can be adjusted by bending
the breaker lever spring. If the pressure is ex-
cessive, it can be decreased by pinching the
spring carefully. To increase pressure,, the
lever must be' removed from the distributor so
the spring can be bent away from the lever.
Avoid excessive spring distortion.
9. Set point opening (.019" for new points).
10.
Reinstall rotor, position and lock distributor cap to
housing.
11.
$tart engine and test dwell and ignition timing.
Eight Cylinder Engine Distributor
1.
The contact point set is replaced as one complete
assembly and only dwell angle requires adjustment
after replacement. Breaker lever spring tension and
point alignment are factory set.
2.
Remove the distributor cap by placing a screw driver
in the slot head of the latch, press down and turn 1/4
turn in either direction.
3.
Remove the two attaching screws which hold the base
of the contact set assembly in place.
4.
Remove the primary and condenser leads from their
nylon insulated connection (fig. 6i) in contact set.
5.
Reverse Steps 2, 3 and 4 to install new contact set.
CAUTION:. Install the primary and condenser
leads as shown in Figure 6i. Improper installa-
tion will cause lead interference between the
cap,
weight base and breaker advance plate.
6. If car has 20,000 to 25^000 miles (or sooner if
desired) the cam lubricator wick (fig. 7i) should be
changed. Using long nosed pliers squeeze assembly
together at base and lift out. Remove all old lubri-
cant from cam surface. Replace in same manner.
Fig.
4i—Breaker Plate and Attaching Parts
Fig. 5i—-Checking Breaker Arm Spring Tension
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE-ELECTRICAL
6Y-21
Fig.
6i—Distributor Lead Arrangements
NOTE:
End of cam
lubricant wick should
be
adjusted
to
just touch
cam
lobes. Over lubrica-
tion
of cam
resulting
in
grease
on
contact points
can-
be
caused
by cam
lubrication wick bearing
too hard against
cam
surface.
A
correctly
ad-
justed
cam
lubricator wick will provide adequate
lubrication
for cam. Do not
apply additional
grease
to cam
surface.
7.
Start engine
and
check point dwell
and
ignition
timing.
ACTUAL
POINT OPENING
.021
.016
FEELER GAUGE
LOCATOR ___JH^H
(ROUND)
V~^3H|
CENTRIFUGAL
\
jdft
ADVANCE
-~-»JBlMBl
MECHANISM
«H
CAM g^k. / X
LUBRICATOR
V^^^
REPLACEMENT
^£9
^-ADJUST
SQUARELY
AND
JUST
TOUCHING
LOBE
OF
CAM
.ROTOR
I^^I^BL
LOCATOR
(PBV 7
(SQUARE)
SBSSF
/
WWjga^/
^/
LUBRICATOR
H^f
CAUTION!
S5y
NEVER
OIL
•-^
CAM
LUBRICATOR-
REPLACE
WICK
WHEN
NECESSARY
Fig.
8i—Inaccurate Gauging
of
Rough Points
SETTING DWELL ANGLE
Four
and Six
Cylinder Engine Distributors
The point opening
of new
points
can be
checked with
a
feeler gauge,
but the use of a
feeler gauge
on
rough
or
uncleaned used points
is not
recommended since accurate
mechanical gauging cannot
be
done
on
such points (fig. 8i).
Contact points must
be set to the
proper opening.
Points
set too
close
may
tend
to
burn and
pit
rapidly.
Points with excessive separation tend
to
cause
a
weak
spark
at
high speed. Proper point setting
for all
models
are:
.019"
for new
points
.016"
for
used points
New points must
be set to the
larger opening
as the
rubbing block will wear down slightly while seating
to the
cam. Contact points should
be
cleaned before adjusting
if
they have been
in
service.
LATERAL
MISALIGNMENT
PROPER
LATERAL
ALIGNMENT
pCORRECT
LATERAL MISALIGNMENT
BY
M
BENDING FIXED CONTACT SUPPORT
[NEVER
BEND BREAKER LEVER
Fig.
7i—Top View
of
Distributor
Fig.
9i—Alignment
of
Points
CHEVROLET
CHASSIS SERVICE /MANUAL
ENGINE-ELECTRICAL 6Y-23
condenser leak or to a defective connection. This
will cause burned points and ignition failure upon
initial starts and at high speeds.
4.
Capacity - Capacity is determined by the area of
the metallic elements and the insulating and im-
pregnating materials.
For a complete check of the condenser, use a tester
which will check for all of the above conditions. Follow
the instructions given by the manufacturer of the
test equipment. Condenser capacity should be
.18-:
23
microfarads.
REPLACEMENT
Four and Six Cylinder Engine Distributor (Fig. 4i)
1.
Release distributor cap hold-down screws, remove
cap and place it out of the work area.
2.
Remove rotor.
3.
Disconnect condenser lead wire from contact point
quick-disconnect terminal.
4.
Remove condenser attaching screw, lift.condenser
from breaker plate and wipe breaker plate clean.
5. Install new condenser using reverse of procedure
outlined above.
Eight Cylinder Engine Distributor
1.
Remove distributor cap.
2.
Loosen condenser lead attaching screw (fig. 6i) and
lift out condenser lead clip.
3.
Remove screw holding condenser bracket to breaker
plate and slide condenser from bracket.
4.
To replace condenser reverse the above procedure.
NOTE:
Make sure that new condenser lead is
installed in proper position (fig. 6i).
DISTRIBUTOR
(BREAKER POINT TYPE)
REMOVAL
1.
On radio equipped Corvettes, remove ignition shield
from over distributor and coil. One bolt is accessible
from top of shield, the other two are at rear of
shield, facing firewall.
2.
Release the distributor cap hold-down screws, re-
move the cap and place it clear of the work area.
NOTE:
If necessary, remove secondary leads
from the distributor cap after first marking the
cap tower for the lead to No. 1 cylinder. This
will aid in the reinstallation of leads in the cap.
3.
Disconnect the distributor primary lead from the coil
terminal.
4.
Scribe a realignment mark on the distributor bowl
and engine in line with the rotor segment.
5. Disconnect vacuum line to distributor and tachometer
drive cable (Corvette). Remove the distributor hold-
down bolt and elamp and remove the distributor from
the engine. Note position of vacuum advance mecha-
nism relative to the engine.
CAUTION: Avoid rotating the engine with the
distributor removed as the ignition timing will
be upset.
Rg.
121-L-6 Distributor-Exploded View
1.
Breaker Plate Attaching
Screws
2.
Condenser Attaching
Screws
3. Condenser
4.
Breaker Plate Assembly
4a.
Cam Lubricator
5. Vacuum Control Assembly
6. Vacuum Control
Attaching Screws
7. Housing
8. Cap
9. Rotor
DISASSEMBLY
10.
Contact Point
Attaching Screw
11.
Contact Point Assembly
12.
Weight Cover
Attaching Screws
13.
Weight Cover
14.
Weight Springs
15.
Advance Weights
16. Cam Assembly
17.
Main Shaft Assembly
18.
Roll Pin
19.
Drive Gear
It is advisable to place the distributor in a distributor
testing machine or synchroscope prior to disassembly.
CHEVROLET CU
SERVICE MANUAL
ENGINE-ELECTRICAL 6Y-24
Fig.
13I-V-8 Distributor (Typical)-Exploded View
1.
2.
2a.
3.
4.
Condenser
Contact Point Assembly
Cam Lubricator
Retaining Ring
Breaker Plate
5.
5a.
6.
7.
Felt Washer
Plastic Seal
Vacuum Advance
Unit
Housing
8.^
Shim
Washer
9. Drive Gear Pin
10.
Drive Gear
11.
Cap
12.
Rotor
13.
Weight Springs
14.
Mainshaft
15.
Advance Weights
16.
Cam Weight
Base Assembly
When mounting distributors for tests, first secure the
gear in the test drive mechanism, then push the distribu-
tor housing downward toward the gear to take up any end
play between the gear and the housing.
NOTE:
When testing distributors that have
their lower shaft support bushing located in the
engine block (6 cylinder engines), a special
adapter should be used to insure the shaft will
run true in its housing.
Test the distributor for variation of spark, correct
centrifugal and vacuum advance and condition of contacts.
This test will give valuable information on distributor
condition and indicate parts replacement which may be
necessary. Check the area on the breaker plate just
beneath the contact points. A smudgy line indicates that
oil or crankcase vapors have been present between the
points.
Four and Six Cylinder Engines
Refer to Figure 12i.
1.
Remove the rotor.
2.
3.
Remove the vacuum control assembly retaining
screws, detach the unit from the distributor housing.
Disconnect the primary and condenser leads from the
contact point quick disconnect terminal, remove the
contact point set attaching screw, condenser attach-
ing screw. Remove the point set and condenser from
the breaker plate.
Remove the breaker plate attaching screws, remove
the breaker plate from the distributor housing (fig.
NOTE:
Do not disassemble breaker plate any
further.
5. Remove the roll pin retaining the driven gear to the
mainshaft, slide the gear from the shaft.
6. Slide the cam and mainshaft from the distributor
housing.
7. Remove the weight cover, and stop plate screws, re-
move the cover, weight springs, weights and slide
cam assembly from the mainshaft.
V-8 Engines
Refer to Figure 13i.
CHEVROLET CHASStS SERVICE MANUAL
ENGINE-ELECTRICAL 6Y-27
timing mark on pulley lines up with timing tab.
2.
Position distributor to opening in block in normal
installed attitude (fig. 15i), noting position of vacuum
control unit.
3.
Position rotor to point toward front of engine (with
distributor housing held in installed attitude), then
turn rotor counter-clockwise approximately 1/8 turn
more toward left cylinder bank and push distributor
down to engine camshaft. It may be necessary to ro-
tate rotor slightly until camshaft engagement is felt.
4.
While pressing firmly down on distributor housing,
kick starter over a few times to make sure oil pump
shaft is engaged. Install hold-down clamp and bolt
and snug up bolt.
5. Turn distributor body slightly until points just open
and tighten distributor clamp bolt.
6. Place distributor cap in position and check to see
that rotor lines up with terminal for No. 1 spark
plug.
7. Install cap, check all high tension wire connections
and connect spark plug wires if they have been re-
moved. It is important that the wires be installed in
their location in the supports.
NOTE:
The brackets are numbered to show the
correct installation. Wires must be installed as
indicated to prevent cross firing.
8. Connect vacuum line to distributor and distributor
primary wire to coil terminal.
9. Start engine and set timing as described under Turn-
Up in Section 6.
BREAKERLESS (MAGNETIC PULSE)
DISTRIBUTOR
REMOVAL (CORVETTE)
1.
If vehicle is equipped with radio, remove three bolts
securing ignition shield over distributor and coil.
One bolt is accessible from the top of shield, the
other two are at rear of shield, facing firewall.
2.
Disconnect tachometer drive cables from distributor
housing.
3.
Disconnect pickup coil leads at connector.
4.
Remove distributor cap.
5. Crank engine so rotor is in position to fire No. 1
cylinder and timing mark on harmonic balancer is
indexed with pointer.
6. Remove vacuum line from distributor.
7. Remove distributor clamping screw and hold-down
clamp.
8. Remove distributor and distributor-to-block gasket.
It will be noted that the rotor will rotate as the
distributor is pulled out of the block. Mark the re-
lationship of the rotor and the distributor housing
after removal so that the rotor can be set in the
same position when the distributor is being installed.
DISASSEMBLY (Fig. 16i)
NOTE:
If a distributor is being disassembled
for replacement of the stationary magnetic
pickup assembly only, it will be necessary to
perform only Steps 3, 4, 5, 7, 8, 9, and 12 of the
service procedure listed below.
1.
Remove screws securing rotor and remove rotor.
2.
Remove centrifugal weight springs and weights.
3.
Remove the tachometer drive gear from the distribu-
tor (Corvette only).
4.
Remove roll pin, then remove distributor drive gear
and washer.
CAUTION: To prevent
magnet, support drive gear
;e to the permanent
?n
driving out roll
pin.
5. Remove drive shaft assembly.
6. Remove centrifugal weight support and timer core
from drive shaft.
7. Remove connector from pickup coil leads.
8. Remove retaining ring which secures magnetic
core support plate to distributor shaft bushing in
housing.
9. As a unit, remove the entire magnetic pickup assem-
bly from the distributor housing.
10.
Remove brass washer and felt pad.
11.
Remove vacuum advance unit.
12.
To reassemble distributor, perform the above steps
in reverse order.
INSTALLATION (CORVETTE)
1.
Check to see that the engine is at firing position for
No.
1 cylinder (timing mark on harmonic balancer
indexed with pointer).
2.
Position a new distributor-to-block gasket on the
block.
3.
Before installing distributor, index rotor with hous-
ing as noted when distributor was removed. Install
distributor in block so that vacuum diaphragm faces
approximately 45° forward on the right side of the
engine and the rotor points toward contact in cap for
No.
1 cylinder.
4.
Replace distributor clamp leaving screw loose
enough to allow distributor to be turned for timing
adjustment.
5. Install spark plug wires in distributor cap. Place
wire for No. 1 cylinder in tower (marked on old cap
during disassembly) then install remaining wires
clockwise around the cap according to the firing
order (1-8-4-3-6-5-7-2).
6. Attach distributor to coil primary wires.
7. Replace distributor cap.
8. Adjust timing and then fully tighten distributor clamp
screw.
9. Attach vacuum line to distributor.
10.
Connect tachometer drive cables to distributor body.
11.
Replace ignition shields.
DISTRIBUTOR OFF-ENGINE TEST
The distributor's centrifugal and vacuum advance can
be checked in a distributor testing machine or synchro-
scope specially adapted or designed to accommodate this
type distributor. However, since this involves removing
the distributor from the engine, this test may be post-
poned until other system checks have been made. A dwell
reading cannot be obtained on this distributor and it is not
likely that the centrifugal or vacuum advance will be a
cause of trouble.
COIL REPLACEMENT
1.
Disconnect ignition switch and distributor leads from
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE-ELECTRICAL 6Y-28
terminals on eoil. On Corvettes equipped with radio,
remove bolts securing ignition shield over distribu-
tor and coil.
2.
Pull high tension wire from center terminal of coil.
3.
Remove the two coil support mounting bolts or loosen
friction clamp screw and remove coil.
4.
Place new coil in position and install attaching bolts
or tighten clamp screw.
5.
Place high tension lead securely in center terminal
of coil and connect ignition switch and distributor
primary leads to terminals on coil. Replace ignition
shield on Corvettes.
6. Start engine and test coil operation.
IGNITION PULSE AMPLIFIER
DISASSEMBLY
To check the amplifier for defective components, pro-
ceed as follows:
1.
Remove the bottom plate from the amplifier.
2.
To aid in reassembly, note the locations of the lead
connections to the panel board.
3.
Remove the three panel board attaching screws, and
lift the assembly from the housing.
4.
To aid in reassembly, note any identifying markings
on the two transistors and their respective locations
on the panel board and heat sink assembly.
5.
Note the insulators between the transistors.and the
heat sink, and the insulators separating the heat sink
from the panel board.
6. Remove the transistor attaching screws, and sepa-
rate the two transistors and heat sink from the panel
board.
7.
Carefully examine the panel board for evidence of
damage.
MOUNTING
SCREW
RESISTOR R5 jgSfe. / DIODE Dl
TRANSISTOR TR2
(UNDERNEATH)
1H L >©V
[So
To
I
/'%**jt\
\
TRANSISTC>R"""
1 X ^^w^ X \ (UNDERNEATH)
9^ESISTORR^^^H|^^^^^H
^B
RESISTOR
R4
^HPH^^H
WM'
RESISTOR
R3
I^B^^^^I^U
N .6 ®
mm
N%|/MOUNTING
• tr^i^w ^\ vjR SCREW
CAPACITOR
Cl\
pNkj^^A^
\
RESISTOR
Rl
MOUNTING ^55S^^ \ CAPACITOR C3
SCREW I RESISTOR R6 CAPACITOR C2
TRANSISTOR TR3
COMPONENT CHECKS (Figs. \7\ and 18i)
With the two transistors separated from the assembly,
an ohmmeter may be used to check the transistors and
components on the panel board for defects. An ohmmeter
having a 1-1/2 volt cell, which is the type usually found
in service stations, is recommended. The low range
scale on the ohmmeter should be used except where
specified otherwise.
A 25 watt soldering gun is recommended, and a 60% tin
40%
lead solder should be used when re-soldering. Avoid
excessive heat which may damage the panel board. Chip
away any epoxy involved, and apply new epoxy which is
commercially available.
In order to check the panel board assembly, it is
necessary to unsolder at the locations indicated in Fig-
ure 18i the two capacitors C2 and C3. In all of the fol-
lowing checks, connect the ohmmeter as shown and then
reverse the ohmmeter leads to obtain two readings. The
amplifier circuitry is shown in Figure 19i.
1.
Transistors TR1 and TR2: Check each transistor by
referring to Figure 20i. If both readings in Step 1
are zero, the transistor is shorted. If both readings
in Step 2 are zero, the transistor is shorted; and if
both readings are infinite, the transistor is open.
Interpret Step 3 the same as Step 2.
2.
Trigger Transistor TR3:
11
both readings in Step 1
are zero, the transistor is shorted. If both readings
in Step 2 are zero, the transistor is shorted; and if
both readings are infinite, the transistor is open.
Interpret Step 3 the same as Step 2.
3.
Diode Dl: 11 both readings are zero, the diode is
shorted; and if both readings are infinite, the diode
is open.
4.
Capacitor Cl: If both readings are zero, the capaci-
tor is shorted.
5.
Capacitors C2 and C3: Connect the ohmmeter across
CHECKING
RESISTOR Rl
UNSOLDER
I
CHECKING TRIGGER
TRANSISTOR TR3
CHECKING
CAPACITOR C
Fig.
171—Pulse Amplifier Panel Board
Fig.
18i—Pulse
Amplifier
Component
Checks
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE-ELECTRICAL 6Y-32
STARTER CIRCUIT
INDEX
Page
General Description 6Y-32
Maintenance and Adjustments . '. . 6Y-32
Resistance Checks 6Y-32
Starting Motor and Solenoid Check 6Y-33
Page
Service Operations 6Y-33
Starter Motor 6Y-33
Removal and Installation 6Y-33
GENERAL DESCRIPTION
The function of the starting system, composed of the
starting motor, solenoid and battery, is to crank the
engine. The battery supplies the electrical energy, the
solenoid completes the circuit to the starting motor, and
the motor then does the actual work of cranking the
engine.
The starting motor (fig. Is) consists primarily of the
drive mechanism, frame, armature, brushes, and field
windings. The starting motor is a pad mounted 12-volt
extruded frame type, having four pole shoes and four
fields,
connected with the armature. The aluminum drive
end housing is extended to enclose the entire shift lever
and plunger mechanism, protecting them from dirt,
splash, and icing. The flange mounted solenoid switch
operates the overrunning clutch drive by means of a
linkage to the shaft lever.
The V-8 wiring harness differs from the in-line engine
in that the ignition lead to the coil from the switch is at-
tached at the coil instead of at the starter solenoid (fig.
2s).
CONTACT
FINGER
PINION
STOP
BRUSH
INSULATED BRUSH HOLDER \ FIELD COIL
BRUSH SPRING ARMATURE
GROUNDED BRUSH HOLDER
OVERRUNNING
CLUTCH
Fig.
Is—Starting Motor Cross Section (Typical)
MAINTENANCE AND ADJUSTMENTS
No periodic lubrication of the starting motor or sole-
noid is required. Since the starting motor and brushes
cannot be inspected without disassembling the unit, no.
service is required on these units between overhaul
periods.
RESISTANCE CHECKS
Although the starting motor cannot be checked against
specifications on the car, a check can be made for. exces-
sive resistance in the starting circuit. Place a volt-
meter across points in the cranking circuit as outlined
below and observe the reading with the starting switch
closed and the motor cranking (distributor primary lead
grounded to prevent engine firing).
1.
From battery positive post To solenoid battery
terminal.
CHEVROLET CHASSIS SERVICE MANUAL
CLUTCH AND TRANSMISSIONS 7-4
5.
Install Tool J-5824 to support the clutch assembly
during removal.
NOTE: Look for "X" mark on flywheel and on
clutch cover. If MX" mark is not evident, prick
punch marks on flywheel and clutch cover for
indexing purposes during installation.
6. Loosen the clutch-to-flywheel attaching bolts evenly
1 turn at a time until spring pressure is released,
then remove the bolts, and remove clutch assembly.
Installation to Vehicle
Clean pressure plate and flywheel face. (They should
be free of oil, grease, metal deposits or burned spots).
1.
Position the clutch disc and pressure plate in relar
tive installed position and support them with align-
ment Tool J-5824.
NOTE: The driven disc on the 4 and 6 cylinder
engines is installed with the damfper springs to
the flywheel side; the V-8 is opposite, however,
THE GREASE SLINGER IS ALWAYS ON THE
TRANSMISSION SIDE.
2.
Turn clutch assembly until "X" mark on cover lines
up with "X" mark oh flywheel, then align cover bolt
holes to nearest flywheel holes.
3.
Install a bolt in every hole and tighten down evenly
and gradually until tight (to avoid possible clutch
distortion).
NOTE: Cover loads are as high as 1-1/4 tons.
4.
Remove pilot tool.
5.
Unhook clutch fork and lubricate ball socket and fork
fingers at release bearing end with a high melting
point grease such as graphite and reinstall fork on
ball stud. On Corvette models use Moly Grease.
6. Lubricate the recess on the inside of throwout bear-
ing collar and the throwout fork groove with a light
coat of graphite grease (fig. 4). On Corvette models
use Moly Grease.
7.
Install clutch fork and dust boot into clutch housing
and install throwout bearing to the throwout fork, then
install flywheel housing.
8. Install transmission as outlined in transmission
section.
9. Connect fork push rod and spring.
10.
Adjust shift linkage as outlined in transmission
section.
11.
Perform linkage adjustment for pedal free play and
check clutch release position.
CLUTCH PEDAL
The clutch pedal is the pendant-type hung from a sup-
Fig. 5 - Release Bearing Lubrication and Comparison
port brace common to the brake pedal and must be re-
moved to remove brake pedal. Refer to Section 5 for
brake and clutch pedal service procedure.
CLUTCH CROSS SHAFT (Figs. 6, 7 & 8)
Removal
1.
Remove linkage return and lower linkage springs and
disconnect clutch pedal and fork push rods from re-
spective cross shaft levers.
2.
Loosen outboard ball stud nut and slide stud out of
bracket slot.
3.
Move cross shaft outboard, and as required to clear
inboard ball stud, then merely lift out to remove
from vehicle.
Repairs
The cross shaft has nylon ball stud seats which should
be inspected for wear or damage. Also check condition
of engine bracket ball stud assembly and special anti-
rattle "O" ring. Figures 6, .7
&
8 show component parts
of cross shaft. Replace parts as necessary based on wear
or damage. Lubricate ball studs and seats with graphite
grease before reassembly.
Installation
1.
Reverse removal procedure to install.
2.
Adjust clutch linkage as previously outlined.
CHEVROLET CHASSIS SERVICE MANUAL